Factor out fixture handling to a separate gem

[ekohl]

Use Case

Currently the fixture code is stored inside this gem, but I have another use case (acceptance testing) where I need it. There I don't need puppetlabs_spec_helper (and would even consider dropping it altogether in Vox Pupuli).

Describe the Solution You Would Like

If the code lived in a separate gem, I could just pull that in.

In addition to that, it could properly spec out the file format and behavior.

Additional Context

I have started https://github.com/ekohl/puppet_fixtures, which has a slightly different implementation to allow for better multi-threading. It uses a simple queue and then each thread processes items in the queue.

The current gem could use more testing and documentation, but I'd like to start the conversation on factoring it out. If we don't agree on it, it can bring a split in the community which I'd prefer to avoid.

[bastelfreak]

@davidsandilands this is part of the effort of aligning the Vox Pupuli and Perforce tooling we talked about. By making PSH more modular it enables us to use it for more usecases.